Adoptive transfer of MDSC or induction of those cells (Arora et al., 2010) has been shown to dampen airway inflammation in a mouse-model for asthma through Arginase-1 and NO synthase-2 (Sendo et al., 2019; Tian et al., 2019; van Geffen et al., 2021). This evidence concerns the gene ARG1 and asthma.